Various types of reverse osmosis (“RO”) systems are used to purify water, generally by removing dissolved impurities and particles larger than about 1.0 angstrom (0.0001 micron). While on one hand, osmosis processes cause a solution with low concentration to diffuse through a semipermeable membrane to a solution with higher concentration until equilibrium is reached, on the other hand, RO processes apply pressure causing a highly-concentrated solution to flow through a semipermeable membrane to a less concentrated solution until the pressure is no longer applied. To cause flow across the semipermeable membrane, however, the applied pressure must be used to overcome osmosis.
In addition to semipermeable membranes, a typical RO system may include prefilters. Sediment prefilters have been used to extend the life of the RO semipermeable membrane by removing suspended sediment to reduce fouling, while carbon filters assist RO membranes in removing chlorine, chloramines, and volatile organic compounds from water. Multiple prefilters, such as Kinetic Degradation Fluxion (“KDF”) filters with carbon filters, may also be used to remove heavy metals and reduce chlorine/chloramine accumulation.
Existing RO systems are not without their problems, however. For example, storage tanks of the typical system create undesirable back pressure, which must be alleviated by a booster pump. Storage tanks and booster pumps require extra maintenance and extra space that is often at a premium for most RO systems. Moreover, storage tanks and booster pumps decrease efficiency by significantly increasing total input into the system while maintaining constant output. While RO systems attempt to provide purified water efficiently, none have achieved success.